Membranes used in membrane filtration processes can fail for various reasons. Conventionally, such failures have been detected using techniques such as particle counting or flow content monitoring. A conventional particle counting technique detects laser light scattering caused by particles in the effluent from the filtration membrane. Other techniques for flow content monitoring include particle sensing, turbidity monitoring, and microbial monitoring. These conventional techniques each have drawbacks such as high cost, low sensitivity, or long response time. There are also so called off-line techniques which can only detect failure when the filtration process is suspended or when the filtration membrane is taken off of the production line.
Accordingly, it is desirable to provide an alternative detection technique.